Circular dichroism in hard X-ray photoelectron diffraction observed by time-of-flight momentum microscopy.

X-ray photoelectron diffraction (XPD) is a powerful technique that yields detailed structural information of solids and thin films that complements electronic structure measurements. Among the strongholds of XPD we can identify dopant sites, track structural phase transitions, and perform holographic reconstruction. High-resolution imaging of kll-distributions (momentum microscopy) presents a new approach to core-level photoemission. It yields full-field kx-ky XPD patterns with unprecedented acquisition speed and richness in details. Here, we show that beyond the pure diffraction information, XPD patterns exhibit pronounced circular dichroism in the angular distribution (CDAD) with asymmetries up to 80%, alongside with rapid variations on a small kll-scale (0.1 Å-1). Measurements with circularly-polarized hard X-rays (hν = 6 keV) for a number of core levels, including Si, Ge, Mo and W, prove that core-level CDAD is a general phenomenon that is independent of atomic number. The fine structure in CDAD is more pronounced compared to the corresponding intensity patterns. Additionally, they obey the same symmetry rules as found for atomic and molecular species, and valence bands. The CD is antisymmetric with respect to the mirror planes of the crystal, whose signatures are sharp zero lines. Calculations using both the Bloch-wave approach and one-step photoemission reveal the origin of the fine structure that represents the signature of Kikuchi diffraction. To disentangle the roles of photoexcitation and diffraction, XPD has been implemented into the Munich SPRKKR package to unify the one-step model of photoemission and multiple scattering theory.

Improving EBSD precision by orientation refinement with full pattern matching.

We present a comparison of the precision of different approaches for orientation imaging using electron backscatter diffraction (EBSD) in the scanning electron microscope. We have used EBSD to image the internal structure of WC grains, which contain features due to dislocations and subgrains. We compare the conventional, Hough-transform based orientation results from the EBSD system software with results of a high-precision orientation refinement using simulated pattern matching at the full available detector resolution of 640 × 480 pixels. Electron channelling contrast imaging (ECCI) is used to verify the correspondence of qualitative ECCI features with the quantitative orientation data from pattern matching. For the investigated sample, this leads to an estimated pattern matching sensitivity of about 0.5 mrad (0.03°) and a spatial feature resolution of about 100 nm. In order to investigate the alternative approach of postprocessing noisy orientation data, we analyse the effects of two different types of orientation filters. Using reference features in the high-precision pattern matching results for comparison, we find that denoising of orientation data can reduce the spatial resolution, and can lead to the creation of orientation artefacts for crystallographic features near the spatial and orientational resolution limits of EBSD.

Determining GaN Nanowire Polarity and its Influence on Light Emission in the Scanning Electron Microscope.

The crystal polarity of noncentrosymmetric wurtzite GaN nanowires is determined nondestructively in the scanning electron microscope using electron backscatter diffraction (EBSD). The impact of the nanowire polarity on light emission is then investigated using cathodoluminescence (CL) spectroscopy. EBSD can determine polarity of noncentrosymmetric crystals by interrogating differences in the intensity distribution of bands of the EBSD pattern associated with semipolar planes. Experimental EBSD patterns from an array of GaN nanowires are compared with theoretical patterns produced using dynamical electron simulations to reveal whether they are Ga- or N-polar or, as in several cases, of mixed polarity. CL spectroscopy demonstrates the effect of the polarity on light emission, with spectra obtained from nanowires of known polarity revealing a small but measurable shift (≈28 meV) in the GaN near band edge emission energy between those with Ga and N polarity. We attributed this energy shift to a difference in impurity incorporation in nanowires of different crystal polarity. This approach can be employed to nondestructively identify polarity in a wide range of noncentrosymmetric nanoscale material systems and provide direct comparison with their luminescence.

Do we really need cadavers anymore to learn anatomy in undergraduate medicine?

With the availability of numerous adjuncts or alternatives to learning anatomy other than cadavers (medical imaging, models, body painting, interactive media, virtual reality) and the costs of maintaining cadaver laboratories, it was considered timely to have a mature debate about the need for cadavers in the teaching of undergraduate medicine. This may be particularly pertinent given the exponential growth in medical knowledge in other disciplines, which gives them valid justification for time in already busy medical curricula. In this symposium, the pros and cons of cadaver use in modern medical curricula were debated and audience participation encouraged.

[Multiple sclerosis and hepatitis B vaccination : What does the verdict of the European Court of Justice on liability after vaccination mean?] / Multiple Sklerose und Hepatitis-B-Impfung : Was bedeutet das Urteil des EuGH zur Haftung nach Impfung?

In June 2017 the European Court of Justice (ECJ) issued a verdict on the legal assessment of the association between hepatitis B immunization and the subsequent manifestation of multiple sclerosis (MS). This led to a high level of insecurity in the medical field as well as the normal population, especially in MS patients. The aim of this article is to briefly present the evidence-based medical facts and in particular to clearly highlight the legal aspects of the abovenamed ECJ verdict.

Quantitative imaging of anti-phase domains by polarity sensitive orientation mapping using electron backscatter diffraction.

Advanced structural characterisation techniques which are rapid to use, non-destructive and structurally definitive on the nanoscale are in demand, especially for a detailed understanding of extended-defects and their influence on the properties of materials. We have applied the electron backscatter diffraction (EBSD) technique in a scanning electron microscope to non-destructively characterise and quantify antiphase domains (APDs) in GaP thin films grown on different (001) Si substrates with different offcuts. We were able to image and quantify APDs by relating the asymmetrical intensity distributions observed in the EBSD patterns acquired experimentally and comparing the same with the dynamical electron diffraction simulations. Additionally mean angular error maps were also plotted using automated cross-correlation based approaches to image APDs. Samples grown on substrates with a 4° offcut from the [110] do not show any APDs, whereas samples grown on the exactly oriented substrates contain APDs. The procedures described in our work can be adopted for characterising a wide range of other material systems possessing non-centrosymmetric point groups.

Diffraction effects and inelastic electron transport in angle-resolved microscopic imaging applications.

We analyse the signal formation process for scanning electron microscopic imaging applications on crystalline specimens. In accordance with previous investigations, we find nontrivial effects of incident beam diffraction on the backscattered electron distribution in energy and momentum. Specifically, incident beam diffraction causes angular changes of the backscattered electron distribution which we identify as the dominant mechanism underlying pseudocolour orientation imaging using multiple, angle-resolving detectors. Consequently, diffraction effects of the incident beam and their impact on the subsequent coherent and incoherent electron transport need to be taken into account for an in-depth theoretical modelling of the energy- and momentum distribution of electrons backscattered from crystalline sample regions. Our findings have implications for the level of theoretical detail that can be necessary for the interpretation of complex imaging modalities such as electron channelling contrast imaging (ECCI) of defects in crystals. If the solid angle of detection is limited to specific regions of the backscattered electron momentum distribution, the image contrast that is observed in ECCI and similar applications can be strongly affected by incident beam diffraction and topographic effects from the sample surface. As an application, we demonstrate characteristic changes in the resulting images if different properties of the backscattered electron distribution are used for the analysis of a GaN thin film sample containing dislocations.

[Physiotherapy, occupational therapy and physical therapy in fibromyalgia syndrome : Updated guidelines 2017 and overview of systematic review articles]. / Physiotherapie, Ergotherapie und physikalische Verfahren beim Fibromyalgiesyndrom : Aktualisierte Leitlinie 2017 und Übersicht von systematischen Übersichtsarbeiten.

BACKGROUND: The regular update of the guidelines on fibromyalgia syndrome, AWMF number 145/004, was scheduled for April 2017. METHODS: The guidelines were developed by 13 scientific societies and 2 patient self-help organizations coordinated by the German Pain Society. Working groups (n =8) with a total of 42 members were formed balanced with respect to gender, medical expertise, position in the medical or scientific hierarchy and potential conflicts of interest. A literature search for systematic reviews of randomized, controlled trials on physiotherapy, occupational therapy and physical therapy from December 2010 to May 2016 was performed in the Cochrane library, MEDLINE, PsycINFO and Scopus databases. Levels of evidence were assigned according to the classification system of the Oxford Centre for Evidence-Based Medicine version 2009. The strength of recommendations was achieved by multiple step formalized procedures to reach a consensus. Efficacy, risks, patient preferences and applicability of available therapies were weighed up against each other. The guidelines were reviewed and approved by the board of directors of the societies engaged in the development of the guidelines. RESULTS AND CONCLUSION: Low to moderate intensity endurance and strength training are strongly recommended. Chiropractic, laser therapy, magnetic field therapy, massage and transcranial magnetic stimulation are not recommended.

[Etiology and pathophysiology of fibromyalgia syndrome : Updated guidelines 2017, overview of systematic review articles and overview of studies on small fiber neuropathy in FMS subgroups]. / Ätiologie und Pathophysiologie des Fibromyalgiesyndroms : Aktualisierte Leitlinie 2017 und Übersicht von systematischen Übersichtsarbeiten sowie eine Übersicht über Studien zur Kleinfaserpathologie bei Subgruppen des FMS.

BACKGROUND: The regular update of the guidelines on fibromyalgia syndrome, AWMF number 145/004, was planned for April 2017. METHODS: The guidelines were developed by 13 scientific societies and 2 patient self-help organizations coordinated by the German Pain Society. Working groups (n =8) with a total of 42 members were formed balanced with respect to gender, medical expertise, position in the medical or scientific hierarchy and potential conflicts of interest. A systematic search of the literature from December 2010 to May 2016 was performed in the Cochrane library, MEDLINE, PsycINFO and Scopus databases. Prospective population-based studies and systematic reviews with meta-analyses of case control studies were taken into consideration for the statements. Levels of evidence were assigned according to the classification system of the Oxford Centre for Evidence-Based Medicine version 2009. The statements were generated by multiple step formalized procedures. The guidelines were reviewed and approved by the board of directors of the societies engaged in the development of the guidelines. RESULTS: Current data do not enable identification of distinct factors in the etiology and pathophysiology of fibromyalgia syndrome. Fibromyalgia syndrome can be associated with inflammatory rheumatic diseases, gene polymorphisms, life style factors (e.g. smoking, obesity and lack of physical activity), depressive disorders as well as physical and sexual abuse in childhood and adulthood. CONCLUSION: Fibromyalgia syndrome is most probably the end result of various pathogenetic factors and pathophysiological mechanisms.

[Complementary and alternative procedures for fibromyalgia syndrome : Updated guidelines 2017 and overview of systematic review articles]. / Komplementäre und alternative Verfahren beim Fibromyalgiesyndrom : Aktualisierte Leitlinie 2017 und Übersicht von systematischen Übersichtsarbeiten.

BACKGROUND: The regular update of the guidelines on fibromyalgia syndrome, AWMF number 145/004, was scheduled for April 2017. METHODS: The guidelines were developed by 13 scientific societies and 2 patient self-help organizations coordinated by the German Pain Society. Working groups (n =8) with a total of 42 members were formed balanced with respect to gender, medical expertise, position in the medical or scientific hierarchy and potential conflicts of interest. A search of the literature for systematic reviews of randomized controlled trials of complementary and alternative therapies from December 2010 to May 2016 was performed in the Cochrane library, MEDLINE, PsycINFO and Scopus databases. Levels of evidence were assigned according to the classification system of the Oxford Centre for Evidence-Based Medicine version 2009. The strength of recommendations was formed by multiple step formalized procedures to reach a consensus. Efficacy, risks, patient preferences and applicability of available therapies were weighed up against each other. The guidelines were reviewed and approved by the board of directors of the societies engaged in the development of the guidelines. RESULTS AND CONCLUSION: Meditative movement therapies (e.g. qi gong, tai chi and yoga) are strongly recommended. Acupuncture and weight reduction in cases of obesity can be considered.

[Drug therapy of fibromyalgia syndrome : Updated guidelines 2017 and overview of systematic review articles]. / Medikamentöse Therapie des Fibromyalgiesyndroms : Aktualisierte Leitlinie 2017 und Übersicht von systematischen Übersichtsarbeiten.

BACKGROUND: The regular update of the guidelines on fibromyalgia syndrome, AWMF number 145/004, was scheduled for April 2017. METHODS: The guidelines were developed by 13 scientific societies and 2 patient self-help organizations coordinated by the German Pain Society. Working groups (n =8) with a total of 42 members were formed balanced with respect to gender, medical expertise, position in the medical or scientific hierarchy and potential conflicts of interest. A literature search for systematic reviews of randomized controlled drug trials from December 2010 to May 2016 was performed in the Cochrane library, MEDLINE, PsycINFO and Scopus databases. Levels of evidence were assigned according to the classification system of the Oxford Centre for Evidence-Based Medicine version 2009. The strength of recommendations was achieved by multiple step formalized procedures to reach a consensus. Efficacy, risks, patient preferences and applicability of available therapies were weighed up against each other. The guidelines were reviewed and approved by the board of directors of the societies engaged in the development of the guidelines. RESULTS AND CONCLUSION: Amitriptyline and duloxetine are recommended in the case of comorbid depressive disorders or generalized anxiety disorder and pregabalin in the case of generalized anxiety disorder. Off-label use of duloxetine and pregabalin can be considered if there are no comorbid mental disorders or no generalized anxiety disorder. Strong opioids are not recommended.

[Definition, classification, clinical diagnosis and prognosis of fibromyalgia syndrome : Updated guidelines 2017 and overview of systematic review articles]. / Definition, Klassifikation, klinische Diagnose und Prognose des Fibromyalgiesyndroms : Aktualisierte Leitlinie 2017 und Übersicht von systematischen Übersichtsarbeiten.

BACKGROUND: The regular update of the guidelines on fibromyalgia syndrome, AWMF number 145/004, was scheduled for April 2017. METHODS: The guidelines were developed by 13 scientific societies and 2 patient self-help organizations coordinated by the German Pain Society. Working groups (n =8) with a total of 42 members were formed balanced with respect to gender, medical expertise, position in the medical or scientific hierarchy and potential conflicts of interest. A systematic search of the literature from December 2010 to May 2016 was performed in the Cochrane library, MEDLINE, PsycINFO and Scopus databases. Levels of evidence were assigned according to the classification system of the Oxford Centre for Evidence-Based Medicine version 2009. The strength of recommendations was achieved by multiple step formalized procedures to reach a consensus. The guidelines were reviewed and approved by the board of directors of the societies engaged in the development of the guidelines. RESULTS AND CONCLUSION: The clinical diagnosis of fibromyalgia syndrome can be established by the American College of Rheumatology (ACR) 1990 classification criteria (with examination of tender points) or without the examination of tender points by the modified preliminary diagnostic ACR 2010 or 2011 criteria.

[Diagnostic Workup and Treatment of Antibody-Related Encephalomyelitis]. / Diagnostik und Therapie von autoantikörpervermittelten Enzephalomyelitiden.

The results of laboratory tests for antineuronal antibodies in immune-mediated encephalitis nowadays are not only relevant for diagnostic purposes but are instead closely connected to outcome measures and treatment response. Besides the mere detection of antibodies, investigating the cerebrospinal fluid is indispensible to rule out an infectious etiology of encephalitis prior to the initiation of immunosuppressive treatment, whereas imaging studies are relevant to gain information on the temporal course of disease and for ruling out other etiologies, e. g. hippocampal gliomas. This work gives an overview on the clinical course and findings of laboratory, electroencephalography (EEG) and imaging studies in relevant types of autoimmune mediated encephalitis. Furthermore, it gives a synopsis on contemporary treatment strategies.

[New strategies for exercise training in osteoporosis]. / Innovatives Bewegungstraining bei Osteoporose.

In the prevention and treatment of osteoporosis, movement with muscle strengthening and proprioceptive training plays a major role. This was taken into consideration in the guidelines by the governing body on osteoporosis (Dachverband Osteoporose, DVO) from 2014 on prophylaxis, diagnosis and treatment of osteoporosis and in the DVO guidelines from 2008 on physiotherapy and exercise therapy for osteoporosis. Increases in lumbar bone density of between 0.5 % and 2.5 % can be achieved in women by strengthening exercises with high resistance. With this combination and strengthening of the quadriceps muscle a reduction of falls and hence the fracture risk could also be achieved. In traumatology, training for muscle strengthening is not always possible, especially for elderly patients. Practically relevant alternatives are regular walking and aquatraining, which may also lead to a significant increase in bone mineral density. Furthermore, large effects can be achieved with alternating side whole-body vibration (WBV) training with whole body vibration plates with only 3 days of training per week and with short training periods (15-20 min). Rates of increase in leg strength between 20 % and almost 40 % and in bone density between 0.5 % and 4 % in 6 months have been described. Whether and with what intensity whole body vibration therapy could be used for e.g. more rapid healing of fractures, is currently unclear. Initial positive results have been described in animal models.

[Infection risks in multiple sclerosis therapy by infusion of disease modifying drugs]. / Infektiologische Risiken in der Multiple-Sklerose-Therapie durch infundierbare Immuntherapeutika.

The increased risk of developing infections when using disease-modifying drugs for treatment of multiple sclerosis (MS) is a major challenge in the daily clinical routine. In the growing field of treatment options specific knowledge of treatment-related risks of infections and appropriate preventive and countermeasures is mandatory. Current clinical experience shows that an individual risk stratification is necessary when choosing treatment options and while monitoring during and after treatment administration. The determination of the individual risk of infection in the context of serial use of disease-modifying drugs remains a challenging issue. In addition to the mechanisms of action, the warning notices and current recommendations on infection prophylaxis when using intravenous disease-modifying drugs, such as alemtuzumab, natalizumab and mitoxantron, are presented in detail.

[Immunotherapy and infectious issues in multiple sclerosis. Self-injectable and oral drugs for immunotherapy]. / Immuntherapien und infektiologische Probleme bei Multipler Sklerose. Selbst injizierbare und orale Immuntherapeutika.

Immunotherapy is generally associated with an increased risk for the development of infections. Due to the continuously expanding spectrum of new and potent immunotherapy treatment options for multiple sclerosis (MS), this article describes the currently known risks for treatment-related infections and the current recommendations for prevention of corresponding problems with drugs used in treatment strategies for MS and their mechanisms of action. The new treatment options in particular are linked to specific and severe infections; therefore, intensive and long-lasting monitoring is required before, during and after treatment and multidisciplinary surveillance of patients is needed. This article gives a detailed review of drug-specific red flags and current recommendations for the prophylaxis of infections associated with treatment of relapsing-remitting MS and when using self-injectable and oral disease-modifying immunotherapeutic drugs.

Chloride transporter KCC2-dependent neuroprotection depends on the N-terminal protein domain.

Neurodegeneration is a serious issue of neurodegenerative diseases including epilepsy. Downregulation of the chloride transporter KCC2 in the epileptic tissue may not only affect regulation of the polarity of GABAergic synaptic transmission but also neuronal survival. Here, we addressed the mechanisms of KCC2-dependent neuroprotection by assessing truncated and mutated KCC2 variants in different neurotoxicity models. The results identify a threonine- and tyrosine-phosphorylation-resistant KCC2 variant with increased chloride transport activity, but they also identify the KCC2 N-terminal domain (NTD) as the relevant minimal KCC2 protein domain that is sufficient for neuroprotection. As ectopic expression of the KCC2-NTD works independently of full-length KCC2-dependent regulation of Cl(-) transport or structural KCC2 C-terminus-dependent regulation of synaptogenesis, our study may pave the way for a selective neuroprotective therapeutic strategy that will be applicable to a wide range of neurodegenerative diseases.

Element-specific Kikuchi patterns of Rutile.

The kinetic energy of keV electrons backscattered from a rutile (TiO2) surface depends measurably on the mass of the scattering atom. This makes it possible to determine separately the angular distribution of electrons backscattered elastically from either Ti or O. Diffraction effects of these backscattered electrons inside the rutile crystal lead to the formation of Kikuchi patterns. The element-resolved Kikuchi patterns of Ti and O differ characteristically, but each can be described fairly well in terms of the dynamical theory of diffraction. Qualitatively, much of the differences can be understood by considering the relative arrangement of the Ti and O atoms with respect to planes defined by the crystal lattice.